The invention relates to a diving apparatus for supplying a diver with breathing air, having a float on which a fresh air line leading from the air atmosphere to the diver is fitted, having a pump which is to be actuated by muscular force and by means of which the diver conveys fresh air via the fresh air line into a fresh air tank which can be worn and fastened on the body of the diver, having a first valve in the fresh air line between the fresh air tank and the air atmosphere, which prevents backflow of the fresh air into the air atmosphere, having a breathing air line which is connected with one end to the fresh air tank, having a mouthpiece which is arranged at the other end of the breathing air line, having a second valve, which is arranged on the breathing air line between the fresh air tank and the mouthpiece, having at least one pulling means, which is actuated at least with a leg or arm and permits the actuation of the pump by the leg or arm movement, and having diving weights which serve to compensate the buoyancy.
Diving apparatuses of this type have already been disclosed in European Patent Application EP 0 297 416. Diving apparatuses of this type are used now and then by sport divers. However, experience has shown that such equipment can give rise to a risk not to be underestimated, particularly for the inexperienced user. Since the diver cannot move in the water independently with such equipment, but always has to be connected via a fresh air line to a float located on the water surface, the likelihood of failure of the vital system components is relatively high. Unforeseeable circumstances such as, for example, kinking of the fresh air line harbor a multiplicity of risks. Consequently, increased safety requirements are to be placed on diving apparatuses of the type mentioned at the beginning.
In the case of diving apparatuses as already known in the prior art, cutting off the fresh air supply can have fatal consequences even at a shallow diving depth. The diver, who is generally neutrally buoyant at a specific depth, first registers the cutting off of the fresh air supply when attempting to breath in after breathing out has already been performed. If it is no longer possible at this instant to breath in, the diver lacks the buoyancy from the breathing air and begins to sink, in particular when the fresh air tank is already filled with water. Such a not unlikely situation is heightened by any amounts of water possibly sucked into the lungs. The average user easily panics in such a dangerous situation because he is greatly circumscribed in his freedom of movement owing to the pulling means and apparatuses fitted on his body.
In addition to the risk from external circumstances that can affect individual components of the equipment, the diver is likewise endangered from simply becoming tired when diving with this equipment. Since a pump movement is required for virtually each breath, diving in this way can be very strenuous. Even at a depth of a few meters, each breath is accompanied by the exertion of a knee bend such as would be executed on land. At greater depths, movement is comparable to a knee bend on land with added weights. Without knowledge of the relevant physical relationships, the normal user easily underestimates this exertion and risk. To make matters worse, there is also a rise in the oxygen requirement with increasing effort. If, for example, the diver does not know that the physical effort for providing the fresh air increases with increasing depth, it can easily happen that the user will gain depth in a brief moment of rest and no longer be capable of carrying out the next pumping movement. As a rule, the diver will just have breathed out in this phase, and so will easily panic. In conjunction with the equipment fastened on his body, there is an increase in the risk of a panic reaction, the more so since carrying out a swimming movement is greatly impaired. Should the diver manage nonetheless to force his way to the surface for safety, he will be completely exhausted. Possibly is lacking in the even the strength to hold on for a relatively long time to the float, mostly a signal buoy.
A further disadvantage of the equipment already known is that the pump is connected to a limb that actuates the pump. The pump is normally actuated via a leg movement, the feet being arranged in stirrups. However, the feet can easily slip from these stirrups during bending of the legs. The consequence is failure of the oxygen supply. In such a situation, reapplying the stirrups to the feet is virtually ruled out, because the diver is firstly no longer getting air and, secondly, is hampered by the fresh air tank, which is located on the chest, as a rule.
Numerous risks proceed from the already known diving apparatus operated by muscular force. A widespread use of this diving technique has so far been opposed by the severe safety shortcomings.